Reciprocable retort base



Aug. 29, 1944- 'r. G. w. WATSON RECIPROCABLE RETORT BASE FiledJune 27, 1942 4 Sheets-Sheet 1 THOMAS GEORGE wlLlllA M WATSGN Zy 7:215 aft-w rn eyar Aug. 29, 1944. T. G. w. WATSON RECIPROCABLE RETORT BASE Filed June 27, 1942 4 Sheets-Sheet 2 M r SM EA smmmw mmmm w .S W KN wm m. J u

Aug. 29, 1944, T WATSON 2,357,244

' RECIPROCABLE RETORT BASE Filed June 27,1942 4 Sheets-Sheet 3 v I five/2Z0? THOMAS GEORGE WILLIAM WATSON Y 33 his ai-Z-qrrzeys 1944- T. G. w. WATSON RECIPROCABLE RETORT BASE Filed June 27, 1942 4 Sheets-Sheet 4 THOMAS GEORGE WlLLlAM WATSON 3371119 a/fivrne ya Patented Aug. 29, 1944;

RECIPRO CABLE RETORT BASE Thomas George William Watson, 'Broolrmansv Park, England, assignor to Taylor Stoker Company Limited, London County, England, a

British Company Application June 27, 1942, Serial No. 448,776 In Great Britain October 6, 1941 15 Claims.

' This invention relates principally to the construction of the bottom of the retort in stokers of the underfeed type but is also applicable to other apparatus within which it is desired to feed granular or semi-fluid material and has for its object the provision of an improved means for actuating the movement of the firebed on such stokers or for actuating the movement of the material on such other apparatus. The invention will hereinafter be described with reference to underfeed stokers with which it is more particularly concerned.

In underfeed stokers the bottom of the retorts usually consist of horizontally reciprocating, pusher blocks arranged alternately with fixed plates and the whole is in stepped formation.

The movement of the fuelwithin the retorts and ofthe superimposed firebed depends on a continuing sequence of action wherein there is advancement of fuel by the pusher blocks on their forward stroke and a collapse of fuel into the space created by the fuel so advanced and the faceof the pusher blocks on their return stroke.

Thus the movement of the firebed depends on the effective collapsing of the fuel in front of the face of each pusher block on its return stroke.

The principal object of the present invention is to provide a means whereby positive and un interrupted motion can be imparted to the firebed,

to the return movement of the base element.v

When the plate is raised it passes upwards through the fuel so that there is no possibility,

during its subsequent forward motion, of theplate not exerting a positive movement on the fuel which exists in front of it in solid condition When at the end of the forward movement of the base, the plate is retracted, the thin space which it originally occupied is readily filled either by the natural collapse of fuel from both front and rear sides or by the assisted collapse which would be caused by the retractable plate when it passes through the fuel prior to its next forward motion.

Th accompanying drawings show how the in-- vention may be carried out in practice, Figure l shows a section through a base element a number of which are to form the base'of a retort for an underfeed stoker. Figure 2 shows a plan of the element. Figure 3 is a section on the line III-III of Figure 1, showing how the base element is supported at each side by a rail fixed to the wall of the retort. Figure 4 is a section taken on the lines IVIV of Figure 1. Figure 5 is an oblique projection of the base element.

The base element is made up of three sections I which are bolted together as shown in the drawings, The middle section is provided with a slot 2 extending across the width of the said section and two side plates 3 are formed at the sides of this section and are integral therewith. These side plate travel along the side walls of the re-' tort as the base element moves and they are provided with bevelled edges 3 and strengthened with horizontal fins 3 so as to offer the minimum of resistance to the fuel, as can be seenyfrom Figure 2. The purpose of these plates is to provide a guide for-the retractable plate 4 and with this object a groove 5 is provided in each plate, the

grooves being in alignment with the slot 2. The.

plate 4 as it rises vertically through the slot is guided and held at its sides in the said grooves. The slot 2 is provided with removable cover plates 2 for holding packings Z in position. These packings serve to prevent fin fuel sifting down through the slot. I

The retractable plate 4 is supported at its lower end by a double link 6 to which it is pivoted, the other end of the link being pivoted to one arm 1 of a bellcrank lever B which is pivoted on a pivot pin 9 which is supported by walls In extending from beneath the base element and'forming a part thereof, as shown in Figure 5. The other arm I l of the bellcrank lever is pivoted on the pin I2 to a link l3 whichis in turn pivoted to an operating lever l4 pivoted on the pin l5 which is supported by bearings Hi. The bearings it are bolted to the wall of the retort and are there-- fore stationary; only one of these bearings .is shown'in Figure 5 but it will be understood that the pin i5 is supported by a bearing H5 at each end thereof. Power is supplied through alink l1 pivoted to the lower end of the operating leveril4.

Figure 3 shows how the base element is supported; Running along the walls l8 of the retort in a horizontal direction are rails l9 which are boltedat intervals to the wall by means of bolted to the underneath side along the said edges.

Assuming that the base element i at the rear end of its stroke with the plate 4 retracted as shown in Figure 1, on the operation of the linkwork the lever [4 will be turned in a counterclockwise direction by the pull of the link 11, the bellcrank lever 8 will be turned in the same direction and the plate 4 will be raised, the base element meanwhile remaining. stationary. When the plate has been raised the required amount the face 22 on the arm H, which is forked, of the bellcrank lever will abut the tops of the two similarly placed bolt 23 on the base element the position of which bolts can be adjusted each by a head 24 and lock nut 25. Further pull upon the bellcrank lever willthereafter be transmitted through the bolts 23 to the base element which is then caused to move forward, i. e., to the left as shown in Figure 1. To obviate the possibility of the base element tending to move forward prior to the retractable plate 4 bein raised two similar counter-weighted levers 26 are mounted on the pivot pin ,9; Each lever 26 is counter-weighted by Y the bottom of the stoker retort, the said element reason of the fact that the end 21 thereof isv larger than the end 28. During the period when theplate 4 is being raised the levers 26 are substantially horizontal with the two lighter ends 28 abutting tw o stationary stops 29 These stops are screwed in similar positions each to one of the twoopposite walls of the retort, The said stops thenprevent any forward movement of the base element with the result that all motion is directed to the plate 4. until it is raisedto its upper limit. As .this occurs, adjustable stops 3!} on th bellcrank lever 8 meet the lugs 3| on the counterweighted levers and push the levers. 26 round on their pivot and so push the ends 28 of the said. levers. away from the stationary stops 29. The base. element is then free to move and is pul d long. t e p ll; n 13 h force being transmitted through the pivot pin l2,to

- the faces 22, the stops 2 3,.an d so direct to thebase element. During this movement the ends 28 of thelevers 2B slide under-the stops 29.

On. the return movement, the linkwork is operated in the reverse direction; and the first effect willzbe to lower the plate 4 during which time .the base. element; will not move. When the plate 4 has. been. lowered to the position where its top edge is flush with the upper surface of the base elementthe faces 22eon the arm ll will meet an opposing, wall 22 below the base element. On further movement of the linkwork the pressure will; be transmitted through the said wall-22 to the. base element which willthen move in the reverse direction, i. e., to the right as viewed in Figure 1, and when the base has reached the limit ofiits return travel the. counter-weighted ends 21 of the levers 26, will, by their weight, cause the other ends 28 thereof to resume the position where they abut the stationary stops 2 9, as shown in Figure 1 I The bottom of each retort will be constituted by several suchbase elements the forward end of each, apart from the last one, overlapping the.

cessitated. by considerations of strength of construction and it is not necessary to have fixed plates between the baseelements. Consequently,

the fall in the level ofthe retort bottom from front to rear of the stoker can, if desired, be. relatively small.

Apart from its use in retorts of underfeed stokers the invention can be applied to the mechanism for feeding fuel from the hopper outlets into the throats of the retorts. In fact, the invention can be embodied in any type of trough or other apparatus within which it is desired to impart a forward feeding action to any type of granular or semi-fluid material.

What I claim is:

1. In a stoker, a reciprocable base element for incorporating a retractable plate movable perpendicularly to said element and operable between a raised position in which said plate projects upwardly from said element and a retracted position in which the upper edge of said plate is lowered to. said element and means for operelement, operating means for said plate arranged to raisethe plate through the slot prior to. the forward movement of the element. toward the ash. pitwhereby the fuel. is. advanced by said plate andto lower saidplate through the slot. prior toithe. return. movement of the element, said plate operating. means forming part of the underneath; part of. the element.

3; A .stoker according to. claim 2, wherein the slot is provided. withv packingitoprevent fine fuel.

sifting between the slot and theplate.

4. A. stoker. according toolaim 2,.wherein the element. has side plates. mounted .at. the sides thereof and extending above the. upper surface of theelement adjacent. to the slot, the saidside plates having grooves in. alignment with the slot acting as guides for the retractable plate.

5. A stoker. accordingto. claim, 2..having. side plates. mounted; at the sides: thereof and extend.-

ing abovethe .upper surface. of. the element ad-.

jacent tothe slot, the saideside. plates, having bevelled. edges .and' horizontal. reinforcing. fins.

and havinggroovesin alignment. with the. slot acting. as guides for thetretractable plate 6; In apparatus having a trough within which it; is. desired toimpart a forward. feeding action to, mate1 'ial; 'a reciprocable base element for the bottom .Of. the. trough, the said. lement incorporating a retractable plate, means to raise the plate to extend upwardly from said element prior to, movementof; thesaid element in one direction whereby'the material is; advanced by. the plate,.

rating a retractable plate movable. perpendlcw.

larly to said element and means for operating said plate to raised and lowered positions, said plate operating means comprising a link mechanismhaving meansdisengaged from said element throughout movement of said plate with respect to saidelement and. engaged with said element at completion of eachmovement, of said plate with respect to said elementto' shiftvsaid element upon further operation of said link o'peratingmeans comprising. alinkmechanismv mechanism, said plate operating means raising said retractable plate before moving said element forward toward the ash pit and lowering said-retractable plate before moving said element away from the ash pit.

8. In a stoker,a reciprocable base element for the bottom of the retort, said element incorporating a retractable plate movable perpendicularly to said element,.means for operating said plate to'raised and lowered positions, said plate operating means comprising a link mechanism ment between two positions of said member, said,

member engaging one of said spaced parts upon completion of each movement of said plate withrespect to said element to shift said element upon further operation of said link mechanism, said plate operating means raising said retractable plate before moving said element forward toward the ash pitv and lowering said retractable plate before moving said element away from the ash pit.

9. In a stoker, a reciprocable base element for the bottom of the retort, said element incorporating a retractable plate movable perpendicularly to said element, means for. operating said plate to raised and lowered positions, said plate operating means comprising a link mechanism having a member operable in opposite directions, spaced parts on said base element engaged by said member for operation of said element, said spaced parts permitting said member free movement between two positions of said member, said member engaging one of said spaced parts upon completion of each movement of said plate with respect to said element to shift said element upon further operation of said link mechanism, said plate operating means raising said retractable plate before moving said element forward toward the ash pit and lowering said retractable plate before moving said element away from the ash pit, and an adjustable stop on one of said parts for adjusting the free movement of said member between said parts before operation of said element by said member whereby to adjust the extent of the movements of said retractable plate by said plate operating means prior to operation of said base element by said plate operating means.

10. In a stoker, a reciprocable base element for the bottom of the retort, said element havin spaced similarly directed projections and incorporating a retractable plate movable perpendicularly to said element, means for operating said plate to raised and lowered positions, said plate operating means comprising a link mechanism including a bell crank lever with an arm having free angular movement from one to the other with respect to said element to shift said elementhavingv means disengaged from said element throughout movement of said plate with respect to said element and engaged with said element at completion of eachmovement of said plate with respect to said element to shift said element upon further operationof said link mechanism', said-plate operating means raising said retractable plate before movingsaid element forward toward the ash pit and lowering said retractable plate before moving said element away fromth'e'ash pit, detent means for preventing;

to raised and lowered. positions, said plate op-- erating means comprising a link mechanism havelementv ing means disengaged from said throughout movement of said plate with respect to said element and engaged with said element at completion of each movement of said plate upon further operation of said link mechanism, said plate operating means raising said retractable plate before moving said element forward toward the ash pit and lowering said retractable plate before moving said element away from the ash pit, a stop member fixed to a stationary part of the retort, a movable member carried by said element and adapted to engage said stop member to prevent said element being prematurely moved forward during the raising of said retractable plate and means on said link mechanism operating said movable member to disengage said movable member from said stop member to release said element as the raising of said retractable plate is completed.

13. In a stoker, a reciprocable base element for the bottom of the retort, said element incorporating a retractable plate movable perpendicularly to said element, means for operating said plate to raised and lowered positions, said plate operating means comprising a link mechanism having means disengaged from said element throughout movement of said plate with respect to said element and engaged with said element at completion of each movement of said plate of said spaced projections, said arm engaging one of said projections at the completion of each movement of said plate with respect to said element to shift said element upon further operation of said link mechanism whereby during movements of said arm between said spaced projections said retractable plate is operated while said element remains at rest.

11. In a stoker, a reciprocable base element for the bottom of the 'retort,.said element incorporating a retractable plate movable perpendicularly to said element, means for operating said plate to raised and lowered positions, said plate with respect to said element to shift said element upon further operation of said link mechanism, said plate operating means raising said retractable plate before moving said element forward toward the ash pit and lowering said retractable plate beforemoving said elment away from the ash pit, a stop member fixed to a stationary part of the retort, a movable member carried by said element and adapted to engage said stop member to prevent said element being prematurely moved forward during the raising of said retractable plate, said movable member being biased to engage said stop member, and a second means on said link mechanism operating said movable member to disengage said movable member from said stop member to release said element as the raising of said retractable plate is completed, said movable member being released by said second means when said plate is retracted.

14. In a stoker, a reciprocable base element for the bottom of the retort, said element incorporating a retractable plate movable perpendicua second means for operating said lever todisenga'gesaid lever from said stop member to release'said element larly to saidelement, means: for operating-said. plateto'raised and loweredpositions, said platev operating means comprising: a link' mechanism I having means disengagedfrom saidelementv throughout movement ofsaid plate with" respect tosaid element'and engaged with said element at completion ofeach movement of said plate with.

respect to said element toshift'said element upon further operation of said linkimech'anism, said plate operating means raising said? retractable plate before moving said element forward toward the ash pit and lowering said retractable plate:

before moving said element away from the ash pit, astop member fixed: to a stationary part oiv the retort, a lever mountedon saidelementandadapted to" engage saidjstop'rnemb'er to preventsaid elementbeing prematurely moved forward during the raising of said retractable plate, and on said link mechanism as the raising of said retractable plate is completed; said lever being freely pivoted-and having' acounterweighted end whereby said lever is:

caused to return to a position engaging said stop member and preventing movement of said element when releasedby said second means andsaid element reaches the end of-v its stroke away from said'ash'pit.

l5. In a stoker, a reciprocable baseelement for the bottom of the retort, said elementincorporating a v retractable plate movable perpendicularly. to said e1ement, m"eans for operatingsaid". plate to raise'd.='and lowered: positions, said plate operatingmeans comprisingva link:mecha.--

nisr n having means disengaged from said element throughout movement of said'plate with respect to said element and: engaged with said,

element at completionvof: each movement of said plater-withi=respe'ct to said element to shift said element: upon further operation of said link mechanismpsaid plateoperating means raising said retractablv plate before. movingv said elemerit: forward toward the ash pit and lowerin saidtretra'ctable plate before moving. said element awayfrom the' ash pit, a-stop member fixed to a stationary; part of the retort',.a lever mounted on' said" element and adapted to engage said stop member to preventsaid element being prematurely moved forward during the raising of said retractable plate, and a second means on said linkmech'anism for operating said lever to disengage saidleverfrom said stop. member to release- 

